1. Field of the Invention
The present invention relates to a radiation detecting cassette having a radiation conversion panel for detecting radiation that has passed through a subject and converting the detected radiation into radiation image information. The present invention also concerns a radiation image capturing system having such a radiation detecting cassette.
2. Description of the Related Art
In the medical field, radiation image capturing apparatus have widely been used which apply a radiation to a subject and guide the radiation that has passed through the subject to a radiation conversion panel, which captures a radiation image from the radiation. Known forms of the radiation conversion panel include a conventional radiation film for recording a radiation image by way of exposure, and a stimulable phosphor panel for storing radiation energy representing a radiation image in a phosphor and reproducing the radiation image as stimulated light by applying stimulating light to the phosphor. The radiation film with the recorded radiation image is supplied to a developing device to develop the radiation image, or the stimulable phosphor panel is supplied to a reading device in order to read the radiation image as a visible image.
In an operating room or the like, it is necessary to read recorded radiation images immediately from the radiation conversion panel after the radiation image has been captured, for the purpose of quickly and appropriately treating the patient. As a radiation conversion panel that meets such a requirement, there has been developed a radiation detector having a solid-state detector for converting radiation directly into electric signals, or for converting radiation into visible light with a scintillator and then converting the visible light into electric signals, so as to read the detected radiation image.
According to some known systems, a radiation conversion panel, a radio communication means, and a battery are housed together in a radiation detecting cassette. The radiation detecting cassette is designed to avoid wasteful power consumption of the battery, which energizes the radiation conversion panel and the radio communication means (see, for example, Japanese Laid-Open Patent Publication No. 2003-172783, Japanese Laid-Open Patent Publication No. 2005-007086, Japanese Laid-Open Patent Publication No. 2005-208269, Japanese Laid-Open Patent Publication No. 2005-173432, Japanese Laid-Open Patent Publication No. 2006-122219, and Japanese Laid-Open Patent Publication No. 2006-158508).
Specifically, Japanese Laid-Open Patent Publication No. 2003-172783 discloses that when a power supply switch disposed on an upper surface, serving as a irradiation surface, of the radiation detecting cassette is turned on, the battery supplies electric power to various components inside the radiation detecting cassette.
Japanese Laid-Open Patent Publication No. 2005-007086 and Japanese Laid-Open Patent Publication No. 2005-208269 disclose that information concerning the remaining amount of stored battery energy is transmitted from a radiation detecting cassette to a controller, wherein the controller inhibits a radiation image from being captured based on the received information.
Japanese Laid-Open Patent Publication No. 2005-173432 reveals that electric power is not supplied from the battery to the radiation conversion panel while a doctor or radiological technician is gripping a handle disposed on the casing of the radiation detecting cassette, whereas electric power is supplied from the battery to the radiation conversion panel when the doctor or radiological technician releases the handle.
Japanese Laid-Open Patent Publication No. 2006-122219 reveals a radiation detecting cassette, which transmits radiation image information (reduced image information) and corrective information to a controller. The controller processes the reduced image information based on the corrective information, so that the radiation detecting cassette reduces power consumption as required, in order to correct the reduced image information.
Japanese Laid-Open Patent Publication No. 2006-158508 discloses that when a mobile image capturing apparatus including a radiation detecting cassette is in motion, unwanted power consumption is prohibited for functions which are not used while the mobile image capturing apparatus is moving.
On the radiation detecting cassette, the power supply switch should be turned on immediately before a radiation image is captured in order to minimize battery power consumption.
According to Japanese Laid-Open Patent Publication No. 2003-172783, however, it is difficult to turn the power supply switch on immediately before the radiation image is captured because, before the radiation image is captured, the subject (patient) is held against an upper surface of the radiation detecting cassette on which the power supply switch also is mounted.
Japanese Laid-Open Patent Publication No. 2005-007086, Japanese Laid-Open Patent Publication No. 2005-208269, Japanese Laid-Open Patent Publication No. 2005-173432, Japanese Laid-Open Patent Publication No. 2006-122219, and Japanese Laid-Open Patent Publication No. 2006-158508 do not disclose any structures or methods for minimizing battery power consumption by turning a power supply switch on immediately before a radiation image is captured.